Donald Trump at a New Hampshire town hall on Thursday did not correct a questioner who said – wrongly – that President Obama is Muslim. Mr. Trump then said, “We’re going to be looking at a lot of different things” to deal with alleged Muslim militia training camps on US soil.

The incident drew an immediate rebuke from at least one of the billionaire’s GOP rivals. New Jersey Gov. Chris Christie said on NBC’s "Today" show that he “wouldn’t have permitted that.” Democratic front-runner Hillary Clinton was more pointed.

“Donald Trump not denouncing false statements about POTUS & hateful rhetoric about Muslims is disturbing, & just plain wrong. Cut it out,” former secretary of State Clinton tweeted on Thursday night.

The exchange in question took place at the beginning of the event. The first questioner, a man in a “Trump” T-shirt, rose and said, “We have a problem in this country. It’s called Muslims. We know our current president is one. You know he’s not even an American.”

At that point Trump answered, saying, “We need this question.” It’s unclear whether he was approving the man’s words or expressing exasperation.

“We have training camps where they want to kill us,” the questioner continued. “That’s my question. When can we get rid of it?”

Trump, who has a long history of dabbling in questionable assertions about Obama’s heritage, took no issue with this. Instead he responded with a semi-generic politician’s answer.

“We’re going to be looking at a lot of different things,” said Trump. “And you know, a lot of people are saying that, and a lot of people are saying that bad things are happening out there. We’re going to be looking at that and plenty of other things.”

Following the New Hampshire event, a Trump spokesman said the billionaire did not hear the reference to Obama's heritage, and was simply saying he'd look into reports about Muslim training camps.

What can we take away from this incident? First, that Trump is no John McCain. When campaigning for president in 2008 Senator McCain handled a town hall questioner who said Obama was “an Arab.”

McCain responded immediately that Obama was “a decent family man, [a] citizen that I just happen to have disagreements with.”

Trump, instead, seems willing to aid and abet strains of thought among his voters that persist despite considerable evidence they aren’t true.

“Real leaders in dealing with the public must feed the truth, and starve ignorance. Trump seems to be feeding ignorance, and starving truth,” tweeted Matthew Dowd, a former Bush-Cheney campaign consultant, in response to the Thursday exchange.

Second, Trump’s anti-immigrant rhetoric has likely attracted a disproportionate number of voters who persist in disbelieving Obama’s US heritage. A whopping 66 percent of Trump supporters believe that the president is Muslim, according to a PPP survey released Sept. 1. Only 12 percent believe, correctly, that Obama is Christian.

Among Republicans generally, 43 percent believe Obama is Muslim, according to a CNN/ORC poll released last week. The comparable figure for US voters overall is 29 percent.

Third, the GOP’s persistent anti-Muslim rhetoric could be alienating a US minority that evinces many Republican values.

Over 20 percent of Muslim-Americans earn more than $100,000, surpassing the national average. Muslim-Americans are well-represented in the American small business community. In general, wealthy business people “will, of course, support lower taxes and smaller government,” writes the Daily Beast’s Dean Obeidallah.